Added a simpel way of handling REST errors using a new RestException? class.

I have tried to introduce Exception handling for errors in the Communication manager. So far, I only committed exceptions for something going wrong. I have been working on a more fine grained distinction between server side errors and client side errors related to REST. however, these errors require some sort of convention for delivering from the server side to the client side. Therefore, they require a convention to be agreed to by NMCDSP and I have not committed these Exceptions.